Aircommand IBIS ROOFTOP CARAVAN Manual - page 5
Page 4
Typical faults or complaints
1: Any complaint accompanied with an error code, see earlier pages.
2: Unit will not work and no display is evident.
Check the following:
Main ECB breaker is set to ON
Mains power is OK at output from ECB
Is the 4 core control cable plugged into the receiver in the inside plenum? Fig 23
Faulty mains connection at the underside of unit. See Fig 11
A blown fuse on the main control board. See fig 1, 2 & 3.
A blown fuse may be caused by a faulty condenser or evaporator fan
Or a faulty fan speed control card (up to serial No 001176)
Poor connection on main board.
The power supply to the main control board is faulty. This condition can be
diagnosed by checking at the breakaway plug between the control cable and the display in the
plenum. See wiring diag. 1 & 1A. If the DC voltage is not attainable there then suspect a faulty
power supply. See onward:
Earlier models had a transformer. See fig 1. Check output by measuring
for 12V AC at the red plug. See fig 1 & 2. If no output replace transformer with an
SMPS.
If unit is of later manufacture and has an external SMPS (fig 4 shows the SMPS
mounted also fig 20) then measure the output at red plug. Should be 12V DC. If no
output, change the SMPS. Some SMPS have an adjustment pot fig 20. Try adjusting
either direction to see if it regains output.
Units from IBSA 03280 have an integrated SMPS on the main board fig 3.
Except for units IBSA 03482 to 03504 which had external SMPS’s
3: Unit drops out the ECB breaker:
Use a 500V megger to check for ground leakage.
It is possible to unplug both condenser fans and the evaporator fan.
Unplug each until the megger shows at least 10Meg
Ω
or greater to earth.
Likewise the compressor can be disconnected to isolate it from the system.
In this way any faulty components can be identified.
Other places to check: earlier models did not have heatshrink on breakaway plugs on the
condenser fans.
Check also the mains connection on the underside of the unit within the 356mm square ceiling
hole.
4: Compressor will not start:
Check that the control board is outputting to the compressor.(yellow wire
from compressor relay). See fig 1, 2 & 3.
Check start and run capacitors. (LHS enclosure see Fig 6) Note: Not all units are fitted with
start capacitors and relays.
Use a clamp ammeter to check for current to compressor. Continuous current
above 6 Amps indicates a faulty compressor.
Check winding continuity:
If a Sanyo: C-RHN1005A or B
Main Wdg. 2.9
Ω
@ 25C
Start Wdg. 6.6
Ω
@ 25C
If an Aisulu: QHR 19E
Main Wdg 2,2
Ω
@ 25C
Start Wdg. 4.2
Ω
@ 25C